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Elevated Levels of Glucose and L‐Fucose Reduce 22 Na + Uptake and Whole Cell Na + Current in Cultured Neuroblastoma Cells
Author(s) -
Yorek Mark A.,
Stefani Mark R.,
Wachtel Ruth E.
Publication year - 1994
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.1994.62010063.x
Subject(s) - veratridine , ouabain , tetrodotoxin , biophysics , fucose , cell culture , sodium , microbiology and biotechnology , chemistry , fructose , neuroblastoma , sodium channel , biology , biochemistry , endocrinology , galactose , genetics , organic chemistry
Na + flux was studied in cultured neuroblastoma cells grown in medium containing increased glucose or L ‐ fucose concentrations. Chronic exposure of neuroblastoma cells to 30 m M glucose or 30 m M L‐fucose caused a decrease in ouabain‐sensitive and veratridine‐stimulated 22 Na + uptake compared with cells cultured in unsupplemented medium. The Na + current, determined by using whole‐cell configuration of the patch clamp, was also decreased in these cells. Tetrodotoxin (3 μ M ), which blocked whole cell Na + currents, also blocked veratridine‐stimulated 22 Na + accumulation. Culturing cells in medium containing 30 m M fructose as an osmotic control had no effect on Na + flux. Specific [ 3 H] saxitoxin binding was not affected by 30 m M glucose or 30 m M L‐fucose compared with cells grown in unsupplemented medium, suggesting that the number of Na + channels was not decreased. These studies suggest that exposing cultured neuronal cells to conditions that occur in the diabetic milieu alters Na + transport and Na + ‐channel activity.